Decode Help Please?

Just got two 833 transmissions and was wondering if anyone could help me with decoding the numbers.

Thanks

Maybe you guys can tell me

The cast iron one reads:
I believe it is out of a 72 Duster

2B501136
PP8333986-043
C99129 H

The aluminum one reads:
I believe this one is an OD

6G18394
FP 833-5337
Author: admin